The thermohydraulic circuits found in the nuclear industry consist of a complex network of horizontal, vertical, or inclined pipes. In particular, the Emergency Core Cooling (ECC) pipes are connected to the primary circuit and are intended to inject cold water into it in accidental situations. Different configurations and inclinations can be found depending on the reactor type. The flow in the ECC pipe, as well as the efficiency of the reactor cooling, are influenced by these different configurations. Therefore, characterizing the flow in these pipes is crucial.
The objective of this thesis is to acquire new experimental data to characterize the water-air flow in an inclined pipe and the trajectory of the exiting jet at atmospheric pressure. The experimental data obtained will be used to develop and/or improve the modeling of flows in inclined pipes.
This thesis should provide the following contributions:
• Set up the experimental facility and the measurement methodologies ;
• Acquisition of the experimental data for different test section geometries (round vs. square), pipe diameter, roughness, inclination, fluid density/viscosity, and flow rate;
• Development of physical models to characterize the flow in an inclined pipe, including liquid hold-up and detachment length;
• Development of a mathematical formulation to predict the trajectory of the exiting jet;
• Study of the impact of stratification in the ECC pipe on the Cocci et al. jet condensation model;
• Optionally, simulation of the experiment using a CFD code (e.g., NEPTUNE-CFD) to extend code validation and identify potential improvements.